The present relation relates to an improved method and apparatus for dispensing a rinse water additive in an automatic washing machine.
The present invention further relates to such a method and apparatus which is especially suited to highly concentrated rinse water additives which are added in relatively small volume, thereby making accurate measurement and avoidance of leakage during the wash cycle critical to obtaining the desired benefits to be provided by the additive during the rinse cycle.
The present invention has further relation to such a method and apparatus wherein the center of gravity of the apparatus and the rinse water additive fluid contained therein is maintained in such position that rinse water is readily able to enter and exit the dispenser during the rinse cycle after the dispensing valve has been opened, thereby ensuring that all of the rinse water additive initially provided in the dispenser is fully utilized during the rinse cycle.
Dosing dispensers for the addition of laundering and softening materials during the washing and rinsing cycles in an automatic washing machine are well known in the art.
Dispensers for adding materials during the rinse cycle in an automatic washer are generally more complex than those employed for adding materials during the wash cycle due to the fact that the rinse additive dispenser is normally inserted when the wash cycle begins and must survive the entire wash cycle without dispensing the material contained inside, yet reliably open during the spin cycle at the conclusion of the wash cycle to deliver the rinse water additive at a point in time which will be effective.
One prior art example of such a rinse water additive dispenser is disclosed in commonly assigned U.S. Pat. No. 3,888,391 issued to Merz on Jun. 10, 1975 and hereby incorporated herein by reference.
Another example of such a prior art rinse water additive dispenser is disclosed in U.S. Defensive Publication No. T993,001 to McCarthy, which was published on Apr. 1, 1980, and which is hereby incorporated herein by reference. Similar examples are found in U.S. Pat. No. 5,267,671, issued to Baginski et al. on Dec. 7, 1993 and U.S. Pat. No. 5,768,918 issued to McKibben on Jun. 23, 1998, both of which are incorporated herein by reference.
Dispensers of the aforementioned type employ a valve means which is automatically opened by centrifugal forces acting upon a counterweight during the spin cycle at the conclusion of the wash operation. After the spin cycle, dispensers of the aforementioned type fall from the wall of the washing machine drum and rinse water floods the dispenser, mixing with and dispensing the additive into the rinse water.
While dispensers of the aforementioned type have functioned adequately for their intended purpose with prior art rinse water additives, trends in the development of more effective rinse water additives have been in the direction of more highly concentrated products which deliver comparable performance benefits to the less concentrated products which they are tending to replace. Typical rinse additive dispensers are generally spherical in shape and employ a fill mark to indicate when the desired amount of additive has been poured into the dispenser. When the volume of product to be added is quite small, accurate measurement thereof is difficult to achieve with prior art style dispensers, namely because even a slight deviation from the fill mark represents a substantial change in product volume. (More specifically, the cross-section of the sphere increases rapidly in the area of the fill mark so that slight deviations from the fill mark represent substantial deviations in the amount of product actually included within the dispenser, particularly if the user overshoots the fill mark. Further, many of the prior art dispensers have a counterweight that cannot be removed during filling and hangs in the device while filling, thereby blocking the filling orifice of the device (and making it more difficult to measure amounts of additives). The counterweight may also skew the volume determination because depending on where the counterweight is stationed during filling, the amount of product measured may be greater or lesser than intended, i.e., the counterweight occupies volume during filling that may or may not translate to the occupied volume anticipated by the fill marks.
An additional problem associated with the prior art dispensing devices is that it is commonly difficult to properly seat the valve means prior to the placement of the dispenser in the washing machine. When not properly seated, these valves tend to either dislodge prematurely during the wash cycle where rinse water additives give ineffective and unsatisfactory results or fail to open at all. An additional problem associated with these devices is that the valve means is commonly not removable from the internal chamber. In such a design, the valve means is an obstacle that interferes with the introduction of rinse water additive into the dispenser leading to spillage and waste.
Accordingly, it is an object of the present invention to provide an improved method and apparatus that makes accurate measurement of the laundry additive into the dispenser relatively easy for the user.
It is another object of the present invention to provide a dispensing apparatus having an improved valve seal design and improved valve assembly design that simplifies the proper seating of the valve means. It is still another object of the present invention to provide a dispensing apparatus having an improved design that will provide an unobstructed opening through which the dispenser may be filled with rinse water additives and easily measured. Protection against premature opening is extremely important for rinse additive dispensers, since premature opening of the dispenser during the wash cycle will most likely result in complete loss of the additive during the wash cycle.
It is still another object of the present invention to provide such an improved rinse additive dispenser which will maintain the center of gravity of the dispenser and the additive contained therein in a position that will ensure the ability of the rinse water to enter and exit the dispenser through the filling/dispensing aperture of the dispenser once the valve used to close the filling/dispensing aperture has moved to its open position to effectively utilize all of the rinse additive originally placed within the dispenser.
The present invention provides a rinse water additive dispenser comprising, a top enclosing a valve housing and at least one opening to allow fluid communication between the valve housing and external environment, a valve assembly that is retained within the valve housing, said valve assembly comprising a resilient valve and counterweight, and a base releasably connected to the top, said base having walls that define an internal chamber for containing a rinse water additive and an opening for receiving the additive and counterweight. The valve assembly has freedom to move within the housing between open and closed positions.
In an additional aspect of the present invention, the resilient valve is located, enclosed, or compressed between the top and base portions of the dispenser when the valve assembly is in the closed position, thereby preventing fluid communication between the internal chamber, the valve housing and the washing machine tub.
In a further aspect of the present invention, dispenser has retaining means for retaining the valve assembly within the valve housing. When the top portion of the dispenser is removed from the base, the attached valve assembly lifts out of the internal chamber. The resilient valve and counterweight of the valve assembly are interconnected by a post that extends through the resilient valve and into the valve housing. The valve housing has a retaining member having an opening through which the upper portion of the post extends. The terminal end of the post has a flange extending radially from the post. Because this flange is too large to pass through the opening of the retaining member the valve assembly is prevented from sliding out of the valve housing. Optionally, the valve post may be telescoping to allow the valve assembly to drop further into the internal chamber.
In a further aspect of the present invention, the valve assembly may include tapered geometry above the counterweight and below the valve in order to assist in proper alignment of the valve along the edge of the internal chamber. This tapered geometry is wider near the valve and narrower near the counterweight, thus helping to properly seat the valve. Optionally, the tapered geometry is formed from (a) a separate part surrounding the counterweight stem between the bottom of the valve and the counterweight and/or (b) the manufacture of the counterweight in such geometry. Optionally, the counterweight stem is cork shaped.
In yet a further aspect of the present invention, the top and base portions of the dispensing device are releasably connected by threads or tongue and groove structures on the top and base portions respectively.
In still yet a further aspect of the invention, the dispensing device will have a generally elliptical cross sectional shape to promote the proper orientation of the device. Likewise, the counterweight may have the same general shape. In addition, it is another aspect of the present invention, that the dispensing device has a protective material of at least a portion of the exterior surfaces of the top and base portions of the device. In addition, it is another aspect of the present invention, that the base portion of the dispensing device may be constructed from one part or from two or more parts that are connected by a snap or tongue-in-grove-feature. The snap feature may be a square undercut snap.